The following relates generally to wireless communication, and more specifically to indicating a number of copied information bits in a retransmission. Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems (e.g., a Long Term Evolution (LTE) system). A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In some cases, wireless communications between a UE and base station may fail—e.g., due to degraded channel conditions, increased interference, etc. Techniques, such as coding schemes and hybrid automatic repeat request (HARQ) operation, may be used by wireless devices to increase the reliability of wireless communications. In some examples, a transmitting wireless device encodes information bits intended for another wireless device and transmits the encoded bits to the other wireless device. Polar encoding may increase the likelihood that the information bits are successfully received at the other wireless device since each encoded bit may provide additional information for decoding another encoded bit. Polar coding aside, a receiving wireless device may still fail to successfully decode received encoded bits, in which case the receiving wireless device may indicate to the transmitting device when a decoding fails. If HARQ operation is active, the transmitting device may then prepare a retransmission using polar coding and transmit the retransmission of the information bits to the receiving wireless device.